Presented in Xth European Symposium on Poultry Welfare Date: 19 June 2017 - 22 June 2017 Venue: ISPAIA - ZOOPOLE développement   City: Ploufragan, France

1. Anatomical pathology and behavioural
reflex responses induced by nonpenetrating
captive bolt devices for on farm euthanasia
of layer chickens
R.M.A.S. Bandara1, S. Torrey1, L. J. Caston1, K. Schwean-Lardner2 and
T. M. Widowski1
1Department of Animal Biosciences, University of Guelph
2 Department of Animal and Poultry Science, University of Saskatchewan,

2. Introduction
• Euthanasia – good death/humane killing
• Ending of a life of an individual to minimize or
eliminate pain and distress ( AVMA, 2013)
• Humaneness of methods based on how quickly
animal lose consciousness
(AVMA, 2013; Raj et al.,2006: Erasmus et al., 2010)
Brain death and
cardiac/
respiratory
arrest
Loss of
consciousness
Rapid loss of
consciousness
Reliable
and
irreversible

3. Pain and unconsciousness
• Pain: “an unpleasant sensory and emotional experience
associated with actual or potential tissue damage”
(IASP, 1979)
• Unconscious/insensible: “a state of unawareness in
which the individual is unable to respond to normal
stimuli, including pain” (EFSA, 2006)
• Insensibility results from lesions to the reticular formation and direct injury to the
cerebral cortex or brain stem
(Parvizi, J., and A. R. Damasio. 2003, Brierley et al., 1971. French, J. D., and H. W. Magoun. 1952)
Reticular formation

4. Cerebral concussion
• Mild traumatic brain injury
• Violent physical shaking of the brain that is responsible for the sudden temporary
loss of consciousness due to disturbances of neural functions usually without skull
fractures. (Plum and Posner, 1980; Bannister, 1992; Rosenthal, 1993; Label, 1997)
• Caused by blow to the head, acceleration forces and explosions
• Cerebral contusion/ hematoma: Severe traumatic brain injury
Bruising of the brain tissue through direct trauma to the head.
Always with loss of consciousness and internal bleeding
Disrupt the
neuronal activities
Cerebral blood flow
is impaired

5. Nonpenetrating captive bolts (NPCB)
• Designed with a blunt bolt that does not penetrate the brain
Kinetic energy = ½ MV2
M= mass of the bolt V= velocity (travel distance) of the bolt
Zephyr-E (120 psi) Zephyr-EXL (98-100 psi) TED

6. Facilitate placement of the tool
Velocity of the bolt is
proportional to the air
pressure
Stunning energy of NPCB
Compressed air
Compressed air
Gas canister
Kinetic energy = ½ MV2
M= mass V= velocity
120 psi
98-100 psi
For chicken
Velocity of the bolt is
changed by the subject
adapter
Z- E
Z- EXL
TED
Hen
Cock

7. Objectives
• To assess the effectiveness of Zephyr-E, Zephyr-EXL and TED for on-
farm euthanasia of different production stages (rearing, growing,
laying and end of production) of layer chickens based on time to
insensibility and death.

8. Methodology
End of
production
Laying
Growing
Rearing
• 25 birds were studied under each age
group for each device
• > 1 application was considered a failure
• Correct positioning of the device
10-11 wks
20-21 wks
30-35 wks
60-75 wks

9. Assessment of insensibility
• Brain stem reflexes
• Time at loss of pupillary reflex
• Time at loss of nictitating membrane reflex
• Time at loss of corneal reflex
• Spinal reflex
• Time at loss of pedal reflex
(pinching of toe) Nictitating
membrane
Dilated
pupil
Constricted
pupil
(Erasmus et al., 2010; Dawson et al., 2009; Raj et al.,1990)

10. Assessment of brain failure and death
• Time at onset of tonic convulsions
• Time at cessation of all convulsions
• Time at cloacal relaxation
• Time at cessation of heart beat
(Erasmus et al., 2010; Dawson et al., 2009; Raj et al.,1990; Blackmore and Delany. 1987)
Cloacal relaxation
Severe contraction of cloaca
Tonic convulsions
Stretching of leg and neck
Clonic convulsions
Severe wing flapping + Paddling Onset of tonic

11. Assessment of postmortem lesions
• Head injuries
• Skin laceration and external bleeding (Y/N)
• Subcutaneous hemorrhages on the head ( 0 - 4 scale system)
• Brain hemorrhages
Macroscopic – Gross subdural hemorrhages (0-4 scale system)
0 1 2 3 4
No
hemorrhage
< 25% 26-50 % 51-75 % > 75 %

12. Skull fractures
0 1 2 3
Intact skull
Depression
fracture
Penetrating
fracture/no
embedded
fragments
Pieces of skull
have broken off
and embedded
into the brain

13. Statistical analysis
• Proc GLM procedure in SAS (ver. 9.4 )
• Variables used to assess insensibility and brain death
• Residuals were normally distributed
• Proc Glimmix procedure in SAS (ver.9.4)
• Score data of postmortem lesions
• Mean separation – Tukey’s Test

14. Results: Time of insensibility
• All brain stem reflexes, pedal reflex and breathing disappeared within
5 seconds for all three NPCB devices
• Five failures were experienced for Zephyr-E — 70 wks old roosters
Pressure down of the air compressor
No adapter application

15. Results: Time of brain failure and death
Device effect
Z-E
(n=94)
Z-EXL
(n=92)
TED
(n= 93)
P
Onset of tonic
convulsions
111.1±4.9 126.1±5.0 121.8±5 0.0920
Cessation of
convulsions
152.4±5.7 b 166.4 ± 5.8 ab 173.6 ± 6 a 0.0315
Cloacal
relaxation
155.6±5.6 b 170.2±5.7ab 179.3 ± 5 a 0.0100
Cessation of
heart beat
176.2±5.8 b 192.6±5.9 ab 201.7 ± 6 a 0.0091
Time in seconds

16. Results: Time of brain failure and death
Age effect
10-11 wks 20-21 wks 30-35 wks 60-75 wks P
Onset of tonic
convulsions
153.8±5.5a 133.4±6.4a 91.6±5.5b 99.8±5.5b
< 0.0001
Cessation of
convulsions
207.2±6.3a 181.7±7.4b 125.1±6.4c 142.6±6.4c
< 0.0001
Cloacal
relaxation
179.3±5.5a 191.6±7.4a 131.9±6.1b 145.9±6.1b < 0.0001
Cessation of
heart beat
236.0±6.5 a 200.9±7.6 b 150.0±6.5 c 173.8±6.5c < 0.0001
Time in seconds

17. Results: Postmortem lesions
• Skin trauma and external bleeding
• Zephyr-E - 79.8%
• Zephyr-EXL - 85.9%
• TED - 82.8%
Skin laceration and external
bleeding

18. Results: Subcutaneous hemorrhage on the head
• Significant device effect ( P < 0.001) — highest score for TED
• Significant age effect ( P < 0.001) — 10-11 week old birds showed highest score
Age (weeks) < 25% > 50%
10-11 0 % 98 %
20-21 9 % 88 %
30-35 12 % 47 %
60-75 14 % 67 %
Device < 25% > 50%
Z-E 12 % 68 %
Z-EXL 12 % 62 %
TED 3 % 88 %
25% of hemorrhage
>75% of hemorrhage - 10 wks old

19. Results: Skull fractures
• No device effect
• Significant age effect (P = 0.001)
60 -75 wk old birds showed lowest score
• Significant device * Age effect ( P = 0.0016)
Age
(weeks)
0 1 2 3
10-11 0 % 26 % 63 % 35 %
20-21 2 % 24 % 60 % 14 %
30-35 1 % 9 % 63 % 27%
60-75 18 % 15 % 42 % 25%
Score 3

20. Results: Gross subdural hemorrhage of the brain
Device effect
• Dorsal side of the brain - Lowest score for Z-E ( P = 0.0001)
• Ventral side of the brain - Lowest score for Z-E ( P < 0.001)
Device < 25% > 50%
Z-E 16 % 40 %
Z-EXL 11 % 57 %
TED 8 % 65 %
Device < 25% > 50%
Z-E 53 % 15 %
Z-EXL 25 % 33 %
TED 34 % 39 %
50 % of hemorrhage
Intact brain
Cerebellum
Cerebrum

21. Results: Gross subdural hemorrhage of the brain
Age effect
Dorsal side of the brain
• 10-11 week old birds showed highest
score ( P < 0.0001)
Ventral side of the brain
• 10-11 week old birds showed highest
score ( P < 0.0001)
Age
(weeks)
< 25% > 50%
10-11 3 % 67 %
20-21 14 % 57 %
30-35 19 % 40 %
60-75 12 % 49 %
Age
(weeks)
< 25% > 50%
10-11 4 % 81 %
20-21 31 % 30 %
30-35 69 % 5 %
60-75 44 % 15 %

22. Conclusion
• All three devices induced immediate insensibility leading to death in
all age groups of layer chickens
• The Zephyr-E had more failures and lower anatomical pathology
scores
• Therefore, the TED and Zephyr-EXL (98-100 psi) appear to be more
efficient for all four production stages of rearing, growing, laying and
end of production for the on-farm euthanasia of layer chickens

23. Acknowledgements
Advisors
• Prof. Tina M. Widowski
• Dr. Stephanie Torrey
Advisory committee
• Prof. P. Turner
• Dr. Karen Schwean-Lardner
Students and volunteers
• Kahlee Latreille
• Linda J. Caston
• Animal behavior and welfare group
• Staff- Arkell Poultry Rsearch Station